The present invention relates to transmit beamforming radio communication techniques and more particularly to techniques for compensating for group delay effects associated with orthogonal frequency division multiplex (OFDM) communication signals.
Examples of transmit beamforming radio algorithms that compute and use transmit weights for transmitting signals to another device are disclosed in U.S. Pat. No. 6,687,492, issued Feb. 3, 2004 and entitled “System and Method for Antenna Diversity Using Joint Maximal Ratio Combining” and in U.S. patent application Ser. No. 10/174,689, filed Jun. 19, 2002. According to these algorithms, receive weights associated with signals transmitted by a second device and received at multiple antennas of a first device are used to compute transmit weights for transmitting signals to a second device. The receive weights will include a group delay term due to group delay ambiguities in the receive synchronization algorithm used in the device for synchronizing to OFDM signals. In order to maintain desired performance of the above-described transmit beamforming radio algorithms, these group delay effects need to be removed.